Expert: Rob Painter - 3/27/2011

Question
QUESTION: I am trying to help out my elder neighbor with his 90 Cadillac.  I used to run a full service auto shop and I need help with this one. We drove the vehicle home from purchase as used and it drove fine no problems.  Then we drove it for a week and it needed a new battery so we put one in no problem.  Then we drove it the next day and it started fine ran great so we go to a friends house that night and the vehicle would not start. No click  nothing.  The lights come on, fuel pump engages, relays kick but nothing when turning key. He wanted to put a starter in I said no but he refused so we did a starter and now samething. I don't know if this has anything to do with this but there is a code E 52 loss of power ECM. Is this going to be the wire in the column, pass key prob or what. Let me know what to do first. Checked all fuses good. like I said worked then some flipped a switch no start. I will be working on this today what should I do first?????? The vehicle does have a Chip in the key.

ANSWER: Hello,

Without seeing what is going on, its very difficult to help you here. I am concerned about the codes which should have nothing to do with the VATS (Passkey). The fact that you say the fuel pump runs also indicates you are not dealing with a pass key issue. The fuel pump won't run if there is a passkey issue. Basically, I think if you bypass the passkey, you will find your problem is still there.

You ould be best off doing what I do to eliminate the guesswork by attempting to get a service manual. I do not know if their information goes back to 1990, but 1990, 1991, 1992 and 1993 are the same body even though the engines are different. I would tell you to go to http://www.alldata.com and see if you can download a factory service manual for $30. This gives you a 1 year access.

All your trouble shooting and diagnostics is there (hopefully alldata goes that far back).

Guessing just costs money and a waste of time. If you can't find a manual at alldata, you may try ebay or craigslist.

You are working in the blind right now and all I can tell you right now from your description, this is not a pass key problem. This may be a bad ECM (Computer) or iring leading to it. Might be a bad ground.

You say you used to have your on shop. This problem is not like doing a simple tune up. This is a computerized car that can have numerous symptoms that can relate back to one component. You can't guess on these cars. You need a factory service manual to diagnose and repair. There is will tell you the reasons there is no power going to the ECM.

If my answer helped you please rate it.

Good luck!









---------- FOLLOW-UP ----------

QUESTION: Thank you very much I do have all data pro and I have fallowed all wireing diagrams and everyuthing seems to be there grounds  and powers along with fueses. If this were you what would you do first. I know he will spend money on this vehicle but not a ton. He has a 88, 89 and now a 90.We found a E 96 12 90  not found and more I will check this out today and I will get back to yous on it thanks p 017.6 297 397 417 518 613 70 80 90 120 1446 160 18 128 20 128 21 22 0 00 23 10 24 25 357. wow where to star

Answer
Hello,

The codes don't do much for me anymore. The system you have became obsolete in 1994 when they went to the OBD II system which is current now. OBD II is much more specific and precise for diagnostics. Look at it this way. One can get the codes from a 90 from just hooking a paper clip between 2 terminals on the diagnostic port and watch the number of times the check engine light flashes compared to installing an electronic scanner into the diagnostic port and everything is read from a Tech II hand held scanner.

See, my memory on the old system is not that great. Yes,I worked on these cars since the first car came out with computers which was the second half of 1980. Where has the time gone? That was 31 years ago--wow!

Good luck!

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